Uniform density cube map rendering for spherical projections

A computer system for rendering a spherical projection as a cube map, said computer system comprising:

• a memory operable for storing data and instructions of an application;
• a processor configured to execute said instructions for controlling rendering of three-dimensional (3D) environments;
• and
• a graphics processing unit communicatively coupled to the processor and the memory, wherein the graphics processing unit is configured to perform, responsive to said instructions, a method of rendering a spherical projection as a cube map, said method of rendering comprising:
• dividing at least one cube face of the cube map into quadrant surfaces;
• assigning viewports to the quadrant surfaces;
• determining coordinates of world-space vertexes projected onto the quadrant surfaces;
• rendering views of the viewports using said coordinates, wherein said views comprise said vertexes;
• and
• expanding the views into the at least one cube face, wherein a pixel density of the views expanded into the at least one cube face is approximately uniform.

A non-transitory computer readable medium comprising a plurality of programmed instructions, which when executed by a processor in a computing device are operable to perform rendering of a spherical projection as a cube map, the programmed instructions comprising:

• instructions to divide at least one cube face of the cube map into quadrant surfaces;
• instructions to assign viewports to the quadrant surfaces;
• instructions to determine coordinates of world-space vertexes projected onto the quadrant surfaces;
• instructions to render views of the plurality of viewports using said coordinates, wherein said views comprise said vertexes;
• and
• instructions to expand the views onto the at least one cube face, wherein the views expanded onto the at least one cube face comprise an approximately uniform pixel density.